CAMRQ1 is an autosomal recessive genetic condition characterized by congenital onset of non-progressive cerebellar ataxia, cerebellar hypoplasia and moderate-to-profound mental retardation. Quadrupedal locomotion has also been observed in some patients. Diagnosis is made based on clinical investigations and neuroimaging. A differential diagnosis must be made between CAMRQ1 and another condition - Marinesco-Sjogren syndrome (MSS). In this context, elevated creatine kinase levels and progressive myopathy distinguishes MSS from CAMRQ1.
Mutations in the VLDLR (very low density lipoprotein receptor) gene are associated with CAMRQ1. VLDLR is a component of the reelin (RELN) signalling pathway, which guides neuroblast migration in the cerebral cortex and cerebellum.
[See: United Arab Emirates > Ali et al., 2012].
Five patients from two consanguineous UAE families of Omani origin were studied by Ali et al. (2012). These patients suffered cerebellar hypoplasia, moderate mental retardation, delayed ambulation and truncal ataxia. The study revealed for the first time, a homozygous missense mutation (c.2117 G>T) on a shared haplotype block in the VLDLR gene in both families.